Voltmeter Fluctuates - Overcharging Issue?

[stationjj]

Hello,

I may or may not have an overcharging alternator problem? I say that, because months ago I did. I hoping I got the the issue resolved? I am not sure because the voltmeter fluctuates some. The CUCV isn't a DD. I am driving more now as weather is warming up for my outdoor fun.

A little background history first.

Late last year I was on a road trip with the CUCV. I started developing an overcharge to the batteries and other devices. I wasn't paying attention to the voltmeter until it was to late. Basically I fried my rear battery and 24 volt inverter. I suspect the problem was with alternator I bought as spare off ebay?

I replaced both batteries, Replaced stock alternators rebuilt by a local shop, and replaced and tightened belts. So the batteries and alternators are fairly new or rebuilt in the last 6 - 8 months. Belts were put on a month ago.

What I have noticed is that voltmeter fluctuates slightly. On recent trip over 100 miles. The voltmeter hung steady between green and red. Battery reading during this time were rear read around 15.4, and the front 14.5. Then today driving around town. The voltmeter was more in the green. Battery readings were Rear 14.5 and front 14.4. Since the repairs voltmeter never hits the RED.

Question am I being paranoid? I have replaced or repaired the obvious batteries, alternator, and belts. Do I have another issue that hasn't been resolved? Is there something I have missed? It getting beyond my pay grade. HAHA! Oddly most ever CUCV owner has issues with under-charging systems.

Thank You for your input and help.

stationjj

 

[cucvrus]

Hey how about a picture of it running in the green. I want to see the type of gauge you have. I have had over charging in the past. I would kick the Sony in my Crown of Thorns M1009 every time above idle. But if you post a picture of the concern and volt gauge reading I may be able to advise. Maybe. ?????

 

[MarcusOReallyus]

I'd just keep an eye on it. Those gauges are old, and not particularly accurate. Since you have checked and gotten 14.1 and 14.5, I'd say you probably don't have a problem.

 

[Tow4]

When you say the voltmeter fluctuates, do you mean you can see it moving up and down while you are looking at it or does it move slowly over time? As everything heats up, you will see the voltmeter change. Mine runs near the top of the green when I first start it and it drops about one needle width after the truck warms up.

14.5 and 14.4 volts are fine. The voltmeter should never hit the red. If the voltage goes high, check to see which battery is getting over charged. Check the connections for that alternator and then disconnect the B+ wire from it if you can't find a bad connection causing the over charge condition. You can drive days with the alternator disconnected. If the voltages are good at the batteries, your voltmeter is bad or has a connection problem.

Here is a link to rebuilding the alternator if you want to know a little more about it.

http://www.steelsoldiers.com/showthread.php?146703-CUCV-Alternator-Rebuild

 

[stationjj]

Thanks for your input. I am good with 14.5 and 14.4 reading. I understand that's a good range around 28.8 volts.

My concern is that the rear will jump up to 15.4. The front stays in normal range around 14.4. At this point I am pushing 29.8 volts. Is this a concern? Sorry I could have worded my question better.

CUCVRUS I will get a picture posted soon.

TOW4 I have noticed it move slightly. It doesn't jump around. The best I can determine is that going down the the highway. The gauge will stay steady between green and red. On recent 100 mile trip it held steady between green and red. I was able to determine when it's between green and red I am pushing around 29.8 volts.

Thanks for your input.

stationjj

 

[Tow4]

If you are not sure of the battery(s) condition, swap the batteries front to back and see if the problem changes. Over 15 volts is not good.

 

[stationjj]

Thanks for your input. I was afraid I still may have a issue. Where did the extra 1 volt come from?

From past research on SS possible problems were Voltage Regulator or Battery.

The alternators should be good. They have been rebuilt in the past 12 months. If it's the alternator I may have another issue? I seem to be rebuilding alternators on 12 - 18 month schedule.
This is for a CUCV that isn't a Daily Driver. It could be the rebuild shop? I don't have the means to rebuild myself.

The batteries are also fairly new as well. I assume they are good. I could be wrong.

My plans are to double check batteries and swap front and rear. Double check my readings. Double check wiring. Did I leave anything out?

I will update this post as needed.

Thanks,

stationjj

 

[Tinstar]

Remember the gauge just shows a ballpark number.
It's not a precision item.

I was also chasing a voltmeter issue.
Three different gauges from three different manufacturers.
Two military, One civilian
Three different readings.

The most accurate of them is the ISSPRO brand. In mine anyway.

Used fluke DM that showed the actual imput never changed and was where it is supposed to be.
On both the batts and Alts.

Fyi

 

[stationjj]

Update; I haven't been able to reproduce the higher voltage readings on a consistent basis. I think I am being paranoid. The behavior of the voltage meter has changed from what I am used to. Today I took 2 photos of the voltage meter as CUCVRUS requested.



Photo 1; This is were I suspect the voltage is high. Sometimes it will stay at this state going down the highway.
Photo 2; The voltage settles to a normal state. 14.4 on both batteries.

In the years that I have owned the CUCV. The voltmeter always stayed consistent as depicted in Photo 2. When that changed I got suspicious.
In the end I may be paranoid from changes? Right now the only thing I can do is monitor battery voltage. I will also check batteries getting to hot.
Unless someone has a suggestion?

Thanks everyone for your help.

stationjj

 

[MarcusOReallyus]

Remember the gauge just shows a ballpark number.
It's not a precision item.

I was also chasing a voltmeter issue.
...
Used fluke DM that showed the actual imput never changed and was where it is supposed to be.
On both the batts and Alts.

This.


I would not be worrying about where 1 volt is coming from. Not even a tiny little bit.

If you just can't let it go, do this:

Make some long jumpers for your voltmeter, hook them up to your batteries (make sure to fuse the hot lead) and run them inside the cab. Do your normal driving and watch your voltmeter to see if it shows a problem.

I'm betting your tired old dash gauge is just lying to you.

 

[usabamaman]

My gauge is usually in the yellow until I gently smack it with the end of a plastic bottle, then it jumps into the bottom of the the green. These gauges are old and not that great. It has been working like this for 3 years. I would be really happy if mine showed high green like yours.